Answer: A.
Explanation:
Máquina térmica tem como função, manter a temperatura de um dado fluído, então, a quantidade de calor desse mesmo fluído ao entrar na máquina, será igual á quantidade de calor desse fluido saindo.
Grassland is the most likely have the deepest layer of topsoil
Topsoil is the outermost layer of the soil that has the highest concentration of of organic matter and microorganism which is very important for plant's growth. Since grassland have a deep layers of topsoil, most of the farmers us it to grow their farm products
Answer:
12
Explanation:
I don't know an explanation used a density calculator
Newton's 2nd law of motion: Force = (mass) x (acceleration)
Divide each side by (mass) : Acceleration = (force) / (mass)
Acceleration of the truck = (4,200 N) / (2,000 kg) = 2.1 m/s²
a. as a moving sound source approaches a stationary observer, the frequency of the sound increases, therefore the wavelength is shorter
Explanation:
This effect is known as Doppler effect. When a moving sound source approaches a stationary observer, the wavefronts of the wave appear to be closer to each other: as a result, the frequency of the sound wave appears to be increased. The wavelength of the sound is inversely proportional to the frequency:
where v is the speed of the wave and f the frequency: therefore, as the frequency increases, the wavelength gets shorter.
b. As the sound source moves away from the observer, the pitch of the sound decreases and the wavelength increases
Explanation:
When the sound source moves away from the observer, the effect is opposite: the wavefronts appear to spread apart from each other, so the frequency of the sound appears to decreases, and as a result, the wavelength increases.
The pitch of a sound is related to how we perceive the sound, and it is directly proportional to the frequency: therefore, since the frequency decreases, the pitch decreases as well.